WILMINGTON, Del. -- Delaware Chief Medical Examiner Richard T. Callery, who oversees the state drug lab that is now the subject of a State Police criminal investigation over missing evidence, has been suspended with pay, officials said Friday.

Callery has led the Medical Examiner's Office since 1997 and earned a $198,500 salary last year, making him the seventh highest-salaried state employee. He was suspended on Tuesday pending the results of an internal human resources investigation.

In an interview Friday afternoon, Gov. Jack Markell said "we certainly have a number of concerns about the management of the office."

"There are a number of things the investigation is reviewing and I can't talk about them today," Markell said.

Investigators have identified 21 cases affected by missing, or tampered with, drug evidence, dating to 2010. The state has had to delay at least two drug trials, dismiss drug charges in one case and cut favorable plea deals with defendants in three other cases.

Delaware Health and Social Services Secretary Rita Landgraf, who suspended Callery, said Hal Brown, deputy director of the office of the Chief Medical Examiner, is in interim charge of the office's operations.

State officials waited three days to publicly announce Callery's suspension, and only did so after questions from The News Journal and criticism from lawmakers.

Republican state Sen. Greg Lavelle called it "troubling" that officials waited three days to announce Callery's suspension. "Where's the transparency?" Lavelle said. "It's not right. The public deserves to know. The Legislature deserves to know."

Problems first surfaced at the Medical Examiner's Controlled Substances Laboratory on Jan. 14 during a drug trial in Kent County Superior Court. A Delaware State Police trooper opened a sealed evidence envelope in front of a jury and instead of finding the 64 blue Oxycontin pills that had been sent to the lab for testing, the officer found 13 pink blood pressure pills.

An investigation soon followed. The lab was shut down and the Medical Examiner's Office evidence locker was secured by the State Police on Feb. 20.

Since then, investigators have been conducting an inventory of all drug evidence at the lab and all police agencies in the state have been asked to double check their records on what drugs had been sent to the lab for processing.

Until it was suspended, the Wilmington-based drug lab conducted verification testing on drug evidence for all Delaware law enforcement agencies.

On Thursday Superior Court President Judge James T. Vaughn Jr. directed that judges would grant delays in all drug cases set for trial in March ‚?? which could involve as many as 150 defendants ‚?? if prosecutors asked for a delay and indicated on the record that drugs in the case were processed by the state's drug lab.